Stabilized photographic silver halide composition

ABSTRACT

PHOTOGRAPHIC COMPOSITIONS CONTAINING A LIGHT-SENSITIVE PHOTOGRAPHIC SUBSTANCE SUCH AS A SILVER HALIDE, AND PHOTOGRAPHIC FILM, PAPER OR PLATE BEARING SUCH A SUBSTANCE, ARE STABILIZED AGAINST DETERIORATION IN STORAGE, BY INCLUDING CERTAIN TRIAZOLOPYRIDAZINE COMPOUNDS IN THE COMPOSITIONS.

United States Patent Int. Cl. G03c 1/34 US. Cl. 96-109 6 Claims ABSTRACT OF THE DISCLOSURE Photographic compositions containing a light-sensitive photographic substance such as a silver halide, and photographic film, paper or plate bearing such a substance, are stabilized against deterioration in storage, by including certain triazolopyridazine compounds in the compositions.

This invention relates to a stabilized photographic composition, and more particularly, it concerns with a light-sensitive silver halide photographic element, e.g. photographic film, paper or plate, bearing on a support a photosensitive layer containing a certain triazolopyridazine compound.

In the art it is well known that photographic compositions, when stored for a long period after their preparation, suffer from decrease in speed and formation of undesired fog. In order to prevent these adverse effects, a variety of stabilizers also have been proposed. Incorporation of the known stabilizers, however, is disadvantageous because it usually causes decrease in speed, and the demand in the art has been directed to develop a stabilizer which will permit to prevent fog without any adverse influence on photographic sensitivity.

It is accordingly one object of the present invention to provide a light-sensitive silver halide photographic composition which can resist to any undesired effect caused by storage over a long period of time. Other objects, features, capabilities and advantages which are comprehended by the invention will be apparent from the specification and claims which follow.

The above-mentioned and other objects can be attained by incorporating a certain triazolopyridazine compound as a stabilizer into a light-sensitive silver halide photographic composition.

We have now found that if a triazolopyridazine compound of the general formula (wherein R means hydrogen, a lower alkyl or lower alkoxy group or halogen and R means a lower alkyl or alkoxy, hydroxy acylamino, benzylamino, cycloalkylamino, alkylolamino or piperidino group) is present in a photographic composition of the present invention, the said composition can be safely stored over a long period of time, without suffering from decreases in speed or formation of fog. In a typical embodiment of the present invention, the above-indicated compound may be incorporated into at least one of the gelatine-containing layers of a photographic element, such layers including emulsion layers, sub-layers, inter-layers, protective layers and backing layers. Another advantage of the present invention is that where the said compound is added to a photographic emulsion during its ripening or digestion, it is possible to prevent fog formation and consequently to facilitate an increase of speed due to the ripening or digestion.

Typical compounds which are included Within the scope of the above-indicated general formula can be listed below:

N N I II N N Compound M.P., o. R R o.

I H CH3 II H OCH3 14a OH Ora-CH2 IV H /CH2 292 CH2-CH2 v H NHCHzCHzOH 263 CHr-CHz VI H NHCH /CH;

CH2CH2 OCH3 OCzHs 173 OH 283 NH0 0 CH3 OHz-CHK XI OH-I5 NH-CH /CH2 CHFCHZ XII OH: NHCHz-Q 1 Above 300 C.

Triazolopyridazine compounds which are useful in the invention can be prepared by a generic process including the reaction of the corresponding 4,5-diaminopyridazine with nitric acid to form a triazole ring. With respect to the particular compound VII, the synthetic process therefor is disclosed in Drug Research 13, 878 (1963).

Incorporation of the triazolopyridazine compound into a layer or layers of the photographic element of the present invention can be made in the manner heretofore known per se in the art. For example, Where the triazolopyrid-azine compound is to be present in an emulsion layer of the said element, it is possible to add the said compound into the emulsion at any time just before, during or after the second ripening of the said emulsion. Addition of the triazolopyridazine compound at the stage after the second ripening of the emulsion is most preferred. Alternatively, it may be added to a starting material for preparation of the emulsion, for example gelatine. The amount of the triazolopyridazine compound to be added will vary depending on the type of emulsions, the degree of stabilization desired and the type of a layer to which the stabilizer is added, but it usually is within the range of from 10 mg. to 2 g. per liter of the silver halide emulsion. It is desirable to add the compound in solution dissolved in a suitable solvent, e.g. water, methanol, ethanol, etc. If the greater amount of the stabilizer is used within the specified range, it is preferred to use Patented Jan. 12, 1971 1 4 an aqueous alkali solution as solvent, because the said Table I. Samples of these film coatings were then exposed stabilizer has a considerable acidity. in an intensity-scale type sensitometer and developed for Use of the triazolopyridazine compound as a stabilizer five minutes in a developer of the following formulation:

does not adversely influence on sensitization of a photographic emulsion concerned Thus the photographic emul- Gram Metol (p-methylaminophenol sulfate) 2.0 sion conta1n1ng the triazolopyndazine compound can be 0 S od1um sulfite (anhydrous) 50.0 sens1t1zed by way of gold-, sulfur, or other chemical sensl- Hydroquinon 4 0 tizatlon or optical sensitization. Furthermore, the sa1d Sodium carbonate (monohydrate) 70 compound sometimes can provlde des1rable effect to facili- Potassium bromide 0.75 tate an increase of speed because it Wlll prevent increased W 1 ater to make 1.0l1ter. fog which frequently occurs accompanying to the sens1t1- zation. It is, of course, true that decrease of speed and The v l p d sa ples W r stopped With dilute acetic increase of fog during storage of the emulsion also can be acid and then fixed, washed and dried. The results are set prevented by use of the triazolopyridazine compound. forth in Table I.

Incubatcd at 55" incubated at 55 C. and 80% RH C. for 3 days for 3 days after Fresh after preparation preparation Amount used Relative Relative Relative (mg./l.) speed Fog speed Fog speed Fog Compound:

Still another advantage of the present invention is that In this test, photographic sensitivity which usually is an fogand densitization both which frequently occur dur ng inverse number of the amount of light exposure to give an the storage of a color photographic material contain ng optical density of 0.1 above fog density, is expressed as the large amount of dye-forming couplers in the emulslon relative speed to that of unstored control film. The data can be effectively prevented by use of the stab1l1zer accordof Table I clearly indicates that the triazolopyridazine ing to the present invention. compounds referred to are useful for prevention of un- The emulsion to which the stabilizer has been added desired fog. can be applied to a suitable support in the manner heretofore known per se in the art, e.g. coating or pouring. 40 EXAMPLE 2 Suitable supports include films, papers and glass plates. The photographic emulsion used in Example 1 is sub- Particularly suitable are films of the types, such as cellujected to second ripening and then sensitized by the addilose esters, e.g. cellulose triacetate; polyesters obtained by tion of dodecylethyleneoxide lauryl ether in the amount the polycondensation of phthalic, isophthalic or terephof 100 mg. per liter of the emulsion. Thereafter, the emulthalic acid with a dihydric alcohol, e.g. polyethylene ter sion is divided to four portions, one of which is used for ephthalate, poly[cyclohexane-1,4 dimethylol]terephthalpreparation of contorl film and the other three used by ate, etc.; and polycarbonates including those obtained by addltion of various triazolopyridazine compounds indithe polycondensation of bis-phenol A with carbonic acid. cated below. Each portion is coated to supports. The films The following examples describe certain wvays in which thus prepared are subjected to the same sensitometric tests the principle of the invention has been applied, but are not as described in Example 1. The results are set forth in to be construed as limiting its scope. Table II.

Incubated at incubated at 55 C. and RH C. for 3 days for 3 days after Fresh after preparation preparation Amount used Relative Relative Relative (mg/1.) speed Fog speed Fog speed Fog EXAMPLE 1 4 EMMPLE 3 A silver iodo-bromide emulsion useful for high speed The silver iodo-bromide emulsion used in Example 1 is added with sodium thiosulfate, as sulfur sensitizer, in the amount of 2 mg. per liter of the said emulsion. Then,

negatives and containing 3% by mole of silver iodide is prepared according to neutral process. This emulsion is 70 subjected to second ripening at a temperature of 60 C. the emulsion is divided to two portions, one of which is for 75 minutes. After the said ripening, the emulsion is not added with any additive and the other is added with divided to six portions, one of which is used for preparathe before-indicated triazolopyridazine compound in the tion of control film and the other five used in combination 75 amount of 50 mg. per liter of the emulsion. Both of the with various triazolopyridazine compounds indicated in non-added emulsion and the added emulsion are sub- TABLE III 20 40 80 100 minutes minutes minutes minutes minutes Control:

Relative speed 60 90 100 105 90 Fog 0. 02 0. 03 0. 05 0. 12 0. 20

Relative speed 50 90 100 120 Fog 0. 02 0. 02 0. 03 0. 04 0.06

From the above table it is clear that the emulsion to which a stabilizer of the present invention is added is favored with the smooth increase of photosensitivity, with the less occurrence of fog, in response to the progress of second ripening, while it shows a relative speed somewhat lower than that of the control emulsion at the earlier stage of said ripening.

EXAMPLE 4 The silver iodo-bromide emulsion used in Example 1 is subjected to second ripening at 60 C. for 75 minutes and then added with a color former solution containing l-(4'-phenoxy-3-sulfophenyl) 3 heptadecyl-S-pyrazolone. The resulting mixture is coated on a film base. On the light-sensitive surface of the thus obtained film, a 3% gelatine solution which is not added or added with the triazolopyridazine compound XV or XVII is coated as a protective layer. Some of the resulting films are stored in the same manner as in Example 1. The stored and unstored films are treated by development with a color developer containing diethyl-p-phenylenediamine, followed by bleaching, water-washing, fixing and then water-washing. The sensitometric test results obtained are set forth in Table IV, which indicates that the incorporation of the triazolopyridazine compound in a protective layer What we claim is:

1. A light-sensitive, photographic silver halide composition comprising light-sensitive silver halide and, as the stabilizer therefor, a stabilizing amount of a compound of the formula NA 1 ll wherein R means hydrogen, a lower alkyl or alkoxy group or chlorine and R means a lower alkyl or alkoxy, hydroxy, acylamino, benzylamino, cycloalkylamino, alkylolamino or piperidino group.

2. A light-sensitive, photographic silver halide composition, as claimed in claim 1, in the form of an emulsion comprising gelatin having a light-sensitive silver halide dispersed therein and containing, as the stabilizer therefor, a stabilizing amount of a compound of the formula wherein R means hydrogen, a lower alkyl or alkoxy group or chlorine and R means a lower alkyl or alkoxy, hydroxy, acylamino, benzylamino, cycloalkylamino, alkylolamino or piperidino group.

3. A light-sensitive, photographic silver halide emulsion as claimed in claim 2; further comprising a member selected from the group consisting of sulfur-, goldand reductive sensitizers.

4. A light-sensitive, photographic silver halide emulsion as claimed in claim 2; further comprising an optical sensitizer.

5. A light-sensitive, photographic silver halide emulsion as claimed in claim 2; further comprising a dye-forming coupler.

6. A photographic element comprising a support bearing thereon a layer of the light-sensitive, photographic also is effective for prevention of fogging. silver halide emulsion as claimed in claim 2.

TABLE IV Ineubated at Incubated at 55 C. and RH C. for 3 days for 3 days after Fresh after preparation preparation Amount used Relative Relative Relative (g./l.) speed Fog speed Fog speed Fog Compound:

Control 100 0.06 40 0.45 30 0.60 XV 1 100 0.05 0.15 80 0.10 1 0.06 85 0.12 75 0.10

References Cited UNITED STATES PATENTS 2,743,180 4/ 1956 Carroll 96109 2,743,181 4/1956 Allen et al. 96-109 NORMAN G. TORCHIN, Primary Examiner R. E. FICHTER, Assistant Examiner 

